ISBN: 978-83-60043-10-3 - eurobic9

Eurobic9, 2-6 September, 2008, Wrocław, Poland
P117. Structural Characterization of a Series of Novel Pt(II) Complex with
1,2,4-triazolo[1,5-a]pyrimidines as Nonleaving Group
I. Łakomska
Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100 Toruń, Poland
e-mail: dziubek@umk.pl
Clinical inconveniences in cisplatin chemotherapy prompted the design and synthesis of more effective and less
toxic platinum based anticancer drugs.
Following this research line, a series of platinum(II) complexes with 1, 2, 4-triazolo[1, 5-a]pyrimidine (tp) (1), 5methyl-1,
2, 4-triazolo[1, 5-a]pyrimidin-7(4H)-one (HmtpO) (2) and 5, 7-dimethyl-1, 2, 4-triazolo[1, 5a]pyrimidine
(dmtp) (3) has been prepared and studied by spectroscopic methods, especially by multinuclear
NMR ( 1 H, 13 C, 15 N, 195 Pt) and IR spectroscopy. Analysis of 1 H NMR spectra revealed, that binding of
triazolopyrimidine to Pt(II) ions results in the deshielding of H(2) and H(6) resonances (∆coord=0.28-0.74 ppm).
However, those changes do not indicate unambiguously which of the heterocyclic nitrogen atoms is engaged in
formation of the platinum-nitrogen bond. This problem was solved by means of 15 N- 1 H HETCOR spectra
analysis. After coordination all signals corresponding to nitrogen atoms in heterocycle ligand are shielding (0.2-
91 ppm). However the biggest coordination shift (∆coord =� 80–91 ppm) was observed for the N(3) signal. Such a
significant shielding of N(3) resonances signal indicates the monodentate coordination to Pt(II) in solution, what
is very important for in vitro test and their application as antitumor prodrugs. Addition, in 195 Pt NMR, the cisdiiodo
compounds were observed between -3143 and -3263 ppm.
The complexes were tested for antitumor activity against three human cells. The results showed that the activities
of these complexes are significantly dependent on the nature of the alkyl group in heterocyclic ligands. The
compounds indicate low in vitro cytotoxic activity of against tested human cancer lines.
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